A semi-finished blank for a varifocal lens comprises a lower substrate whose upper face has a convex curve, an upper substrate that has a lower face with a concave curve and that is joined opposite this upper face, etc. A varifocal section composed of a liquid crystal material is disposed between the upper and lower substrates.
Varifocal eyeglasses are obtained from such a semi-finished blank for a varifocal lens, by going through a specific process. Varifocal eyeglasses allow the refractive index to be changed by applying voltage to the varifocal section, and can be used as bifocal eyeglasses, for example (see Patent Literature 1).